Highlights Postoperative neurological complications are not rare in ACDF for OPLL pathology. Multimodal IONM may reduce neurological damage in ACDF surgery for OPLL. IONM and preoperative myelopathy were associated with neurological complications.

The platelet-derived growth factor receptor-β (PDGFR-β) has a number of conserved cysteine residues on its cytoplasmic domain. We have examined whether the cysteine residues play a role in the enzymic function of PDGFR-β. We found that N-ethylmaleimide, which selectively alkylates free thiol groups of cysteine residues, completely inhibited the kinase activity of PDGFR-β. We then identified, through site-directed mutagenesis, two conserved cysteine residues critical for the enzymic function of PDGFR-β. Cys to Ser mutations for either Cys-822, positioned in the catalytic loop, or Cys-940, located in the C-terminal kinase subdomain, significantly reduced the activities of autophosphorylation and phosphorylation towards exogenous substrates. The non-reducing gel analysis indicated that neither of these cysteine residues contributes to the kinase activity by disulphide-bond formation. In addition, the individual mutation of Cys-822 and Cys-940 had no effect on protein stability or the binding of substrates or ATP, implying that these cysteine residues are involved in enzyme catalysis. Finally, proteolytic cleavage assays showed that the mutation of Cys-940, but not Cys-822, induced a protein conformational change. Taken together, these results suggest that Cys-940 contributes to the catalytic activity of PDGFR-β by playing a structural role, whereas Cys-822 contributes through a different mechanism.

BackgroundIt would be imprecise to generalize the vertebral level determined by palpation to patients of all ages. The purpose of this study was to compare the vertebral level passed by Tuffier's line in elderly women with that passed in adult women using ultrasound in the left lateral decubitus flexed position.MethodsWe enrolled 50 female patients over the age of 65 (elderly group) and 50 female patients between ages 20 and 50 (control group) who had been scheduled to undergo spinal anesthesia. Using ultrasound, we marked the L2–5 lumbar spinous processes and intervertebral spaces. The most cephalad part was labeled 1 and the most caudal part was labeled 11. We then identified which line of these vertebral levels Tuffier's line crossed.ResultsThe median value of the numbers signifying the vertebral level of Tuffier's line was 3 (the L2–3 intervertebral space) in the elderly group, while it was 8 (the lower part of the L4 vertebra) in the control group. The vertebral level of Tuffier's line had statistically significant correlations with age, body mass index, and weight in the elderly group (P < 0.001).ConclusionsThe vertebral level of Tuffier's line determined with ultrasound measurement in the left lateral decubitus flexed position was more cephalad in the elderly women than in those of the control group. Therefore, we should consider that the needle could be inserted at a higher level than expected, and use care in determining the level of needle insertion during spinal anesthesia in elderly women.